Solar cell elements convert solar energy into electrical energy.
A conventional method for manufacturing a solar cell element will now be described. A semiconductor substrate with a first conductivity type is prepared. The semiconductor substrate is subjected to gaseous diffusion in such a manner that the semiconductor substrate is exposed to an atmosphere containing an impurity with a second conductivity type at high temperature, whereby a second conductivity-type layer is formed in the semiconductor substrate. When the semiconductor substrate is of a p-type, an n-type layer is formed in the semiconductor substrate and therefore a pn junction is formed between the n-type layer and a p-type layer. Electrodes are each formed on a light-receiving surface of the semiconductor substrate and the back surface thereof, whereby the solar cell element is obtained.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2-60172